Radial turbo compressors of the design in which a shaft with one or more compressor impellers is arranged between two bearings (“single shaft compressor”) generally comprise a housing which is characterized either by a horizontal or by a vertical separation. If these turbo compressors are exposed to corrosive media, the housings as a whole may consist of a corrosion-resistant material or be lined or coated with a corrosion-resistant material in regions in contact with the media. In plant construction in the chemical industry and for the oil and gas sector, it is very common to produce a corrosion-resistant layer by deposition welding with a corrosion-resistant alloy. Depending on the corrosivity of the media concerned, stainless steels with corresponding composition or also nickel-based alloys may be used. Whereas this procedure is applied with a high degree of automation for compressor housings with a vertical separating joint, when applied to housings with horizontal separating joints, difficulties arise because of their more complex geometry and the tendency towards severe distortions because of the weld stresses.
Compressors with horizontal separating joints are made either integrally of a corrosion-resistant alloy, or protected at great expense with a combination of cladding with corrosion-resistant panels and deposition welding. Here, a suitable weld sequence is necessary, in combination with controlled heat application during welding, with the aim of minimizing the stresses and hence distortions.
The procedure as described above is disclosed at least partially in US 2011/0232290A1 for a housing with vertical separating joint (casing-cover design).